Vacuum tube



Jan. 25, 1949.

P. G. CHEVIGNY ET AL VACUUM TUBE 5 Sheets-Sheet l Filed March 26,\ 1945 1N NToRs P14/UL 6'. C V/NY CHRSON MEA/ E146 WHEEL Filed March 26, 1943 Jan. 25, 1949.

VACUUM TUBE P. G. cHEvlGNY ET AL 75 Sheets-Sheet 2 dU2 L58 INVENTORS Paz/L G. cHEw/vv BYmAso/v MSM-HG WHEELER A'TTRNEY Patented Jan. 25, 1949 airco sTArEs 'OFFICE VACUUM TUBE Application March 26, 1943, Serial No. 480,662

This invention relates to improvements in vacuum tubes. and more particularly to novel arrangements for the mounting of cathodes in magnetrons.

An object ci this invention is to provide a novel magnetron construction having large heat-dissipating surf aces.

Another object of this invention is directed to novel arrangements i'or mounting the cathode in such magnetrons.

A further object of this invention is to provide improved lead-in arrangements for supporting the cathode in a magnetron.

Other objects will become apparent irom'the following description taken in connection with the attached drawings showing several illustrative embodiments of the invention, and wherein:

Fig. 1 is a longitudinal broken cross-sectional view of a preferred form of magnetron structure formed in accordance with the present invention;

Fig. 2 is a transverse cross-sectional view taken along line II-II of Fig. l;

Fig. 3 is a partial broken longitudinal sectional view of a modified form of magnetron cathode mounting;

Fig. 4 is a transverse cross-sectional view taken along the line IV-IV of Fig. 3;

Fig. 5 is a broken partial longitudinal crosssectional view of still another form of lead-in construction; and

Fig. 6 is a transverse cross-sectional view taken along the line VI-VI of Fig. 5.

ln the preferred form of invention illustrated in Figs. 1 and 2, the magnetron is formed oi a hollow metal pipe lil whose central bore i!` is preferably, but not necessarily, formed square. A cathode l2 is placed within the bore il and within a transverse opening i3 extending through one wall oi the pipe. Opposed magnets i4, l' are adapted to be positioned about the pipe il opposite the cathode i2. One end ci the ipe lil is formed with a seal which may consist of a cap i6 screwed about the end of the pipe l0.'

For the purpose of coupling the magnetron output to other devices, the cap i6 may be formed with a central opening and presses a copper disk i8, having a narrow slot 2i), against the end of the pipe. A mica disk 22 is placed over the open end of the copper disk I8 and may be sealed to the cap l5 by suitable mean-s, such as a varnish seal. It is to be understood however, that the coupling seal just describedmay be replaced by other types of seals or coupling devices, such for example, as described in the copending applica- 12 Claims. (Cl. Z50-27.5)

2 tion of P. G. Chevigny, S. N. 481,314, filed March 26, 1943 now Patent No. 2,419,536.

The other end of the pipe lil is also sealed as by a cap 2s. This cap -covers the central bore H but is provided with a pair of lspaced openings into which are fitted outwardly extending sleeves 2S, 2t aligned with small longitudinal bores 23, 28 communicating with'the cavity formed by the intersection of the transverse passage i3 with the central bore li. The outer ends of the sleeves 25, 26 are sealed as by glass seals 3%, 3Q respectively, through which extend lead rods 32, 32. These rods project outwardly from the seals 38, 3B' ,and inwardly through the sleeves 26, 25' and bores 23, Z8 for connection with the cathode l. This cathode which is preferably formed of a hollow cylinder provided on. its outside with some suitable electron-emitting coating lis formed at one end with an extension 34 held in a bushing 36 attached to the end of the one lead 32. With in the cathode l2 is a suitable heating element such as a spiral filament 33 which is connected at one end to the extension 35i and at its other end to the other lead rod 32'. The passage i3 is closed -on the outside by a cap @il which is sealed in place in any suitable manner after the parts have been assembled within the passage.

lt will thus be seen from a study of Figs. 1 and 2 that we have provided a magnetron structure in which all parts are readily accessible and which, while the various electrodes are mounted within a sealed evacuated chamber, provides a larger heat-dissipating surface for the pipe il! vwhich forms the anode and the outer portion of the resonant chamber of the tube. As a result, the tube may not only be Voperated at extremely high frequencies but since the pipe l2 is accessible for readily cooling by any suitable well-known means, (not shown) it is capable of handling large amounts of power.

In Figs. 3 and e we have illustrated a modiiled arrangement in which the leads for the cathode extend transversely through the side walls of the pipe rather than longitudinally thereof, as in Figs. l and 2. As is shown in Figs. 3 and 4, the tube again is formed of a long hollow pipe lili whose central bore lll is preferably of square cross-section. The cathode H2 is mounted ln a similar transverse passage H3 while opposed magnets Ht, lill are positioned about the pipe on opposite sides of the cathode; In this case, however, the hores t28, 25' extend transversely tthrough one C all oi the pipe l IB and communicate with the cavity formed by the intersection of the transverse passage l I3 with the longitudinal bore I i. Sleeves |215, |25 are fastened partially within the bores |28 and |28 respectively, and their outer ends are covered by glass seals |36. |30. Lead |32 extends through the glass seal |30 at one end and connects with the extension |34 on one end of the cathode H2 by means of the bushing |36. The other lead |32 extends outwardly through the seal |30 and inwardly through the sleeve |26 and bore |28 to within the central cavity where it is connected to the lower end of the heating coi1 |38. A cover |40 closes the passage H3. On-e end of the pipe H may be sealed with a coupling seal as in the manner described in connection with Figs. 1 and 2, while in this case the other end will be formed 4by a straight seal which may be in the form of a cap |24. i

In the form of invention illustrated in Figs. 5 and 6, the cathode leads extend transversely into the pipe in alignment and from opposite sides. Again, the magnetron consists essentially of a hollow longitudinal pipe 2H) having a preferably square central bore 2l A cathode 2|2 is positioned within the bore 2H at the inter-section of the latter with a transverse passage V2|'3. Magnets 2M, 2M are positioned outside of the pipe 2| i) on opposite sides of the cathode 2|2.

The bores 228 and 228 extend outwardly through the walls of the pipe 2| at right angles to the central bore 2 but in alignment with one another. The bore 228 contains an outwardly extending sleeve 226 whose periphery is closed by a glass seal 23|3. A lead 232 passes through the seal 230 inwardly to the cathode. The bore 228 contains the outwardly projecting sleeve 226' whose periphery is covered by the glass seal 230'. The lead 232 extends through this glass seal and inwardly toward the cathode 2| 2. The cathode 2|2 in this oase is formed with a tab 25| extending upwardly from the extension 234 and attached to one end of the lead 232 and a surround- 238 extends through an opening at the top of the cathode and is attached to the inner end of the lead rod 232.

It will be clear to those skilled in this art that the modifications illustrated in Figs. 3 to 6 inclusive are fundamentally similar to the preferred form of construction illustrated in Figs. 1 and 2, but provide for diierent arrangements of the tube which, under various circumstances may be more suitable than the construction shown in the preferred form. The essential feature, namely, providing a large accessible anode surface which can be readily cooled for the purposes of increasing the handling capacity of the tube is present in all forms of the invention.

While we have illustrated in connection with the present invention only one type of cathode structure, it will be clearly understood by those skilled in this art that the arrangement of cathode leads in accordance with the present invention permitsthe use of various other types of cathodes, for example, one might use a cathode indirectly heated by bombardment, as is shown in the copending application of P. G. Chevigny, S. N. 474,968, led February 6, 1943, now Patent No. 2,411,506, or a directly heated cathode may be used as well as an indirectly heated cathode. Therefore, while we have described above the principles of our invention in connection with certain specific apparatus and particular modifications thereof, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of our invention as set forth in the objects and the accompanying claims.

We claim:

l. An electron discharge device, including a hollow metal pipe formed with a transverse passage in one wall leading to its central bore and forming therewith a central cavity, and a pair of relatively smaller bores extending through its walls at an angle to said passage and communieating with said cavity, a cathode positioned within said cavity, cover means sealing the open end of said passage, a pair of cathode leads each attached at one end to said cathode and extending through said smaller bores outwardly oi said pipe, means sealing the outer ends of said smaller bores and supporting said leads therein, a pair of magnets, one positioned on each side of said pipe in alignment with said cavity, and means sealing both ends 'of said pipe.

2. The combination according to claim 1, in which said cathode comprises a hollow cylinder and a heating coil positioned therein, said cylinder being disposed coaxially with respect to said cavity with one end of said coil connected to said cylinder, and in which one of said leads is connected to one end of said cylinder and supports the same, and the other lead is connected to the other end of said heating coil.

3. An electron discharge device, including a hollow metal pipe formed with a transverse passage through one wall leading to its central bore and forming therewith a central cavity, and a pair of relatively smaller bores extending through its walls at an angle to said passage and communicating with said cavity through one side thereof, a cathode positioned within said cavity, cover means sealing the open end of said passage, a pair of cathode leads each attached at one end to said cathode and extending through said smaller bores outwardly through said pipe, means sealing the outer ends of said smaller bores and supporting said leads therein, a pair of magnets, one positioned on each side of said pipe in alignment with said cavity, and means sealing both ends of said pipe.

4. The combination according to claim 3, in which said cathode comprises a hollow cylinder and a heating coil positioned therein, said cylinder being disposed coaxially with respect to said cavity with one end of said coil connected to one end of said cylinder, and in which one lead is connected to the said one end of the cylinder, and the other lead to the other end of the heating coil.

5. An electron discharge device. including a hollow metal pipe formed with a transverse passage through one wall leading to its central bore and forming therewith a central cavity, and a pair of relatively smaller bores extending longitudinally through its walls from one end of the pipe to the central cavity, cover means sealing the open end of said passage, a cathode positioned pair of magnets, each side oi said pipe and in alignment with said cavity.

l6. The combination according to claim 5, in which the sealing means for the one pipev end includes a cap on the end of the pipe closing the central bore and having a through aligned with said sleeve in each opening projecting outwardly therefrom, and a glass seal about the outer periphery of each sleeve and surrounding the enclosed leads.

7. An electron discharge device, including a hollow metal pipe formed with a transverse passage through one wall leading to its central bore and forming therewith a central cavity,`and a pair of relatively smaller bores extending through its wall at an angle through said passage transversely to the axis of the central bore and communicating with said cavity, a cathode positioned within said cavity, cover means sealing the open end of said passage, a pair of cathode leads each attached at one end to said cathode and extending through said smaller bores outwardly of said pipe, means sealing the outer ends ci said smaller bores and supporting said leads therein, a pair oi magnets, one positioned on each side of said pipe in alignment with said cavity and means sealing both ends of said pipe.

8. The combination according to claim 7, in which the sealing means for said smaller bores comprises a metal sleeve in each bore extending outwardly through the walls of said pipe and a glass seal about the outer periphery of each sleeve sealing the same and surrounding the outwardly extending lead.

9. The combination according to claim 7, in which said smaller bores communicate with said central cavity through one end of said pipe.

10. An electron discharge device, including a hollow metal pipe formed with a transverse passage through one wall leading to its central bore and forming therewith a central cavity, and a pair of parallel transverse smaller bores extending through another wall and communicating with said cavity, cover means sealing the outer end of said passage, a cathode positioned within said cavity, said cathode comprising a hollow cylinder and a heating coil positioned therewith having one end attached to one end of the cylinder, a pair of cathode leads extending through said smaller bores outwardly of said pipe, one cathode lead being connected to the one end of the cylinder and the other cathode lead being pair of openings theresmaller bores, a metal connected to the other end of said heating coil, a metal sleeve in each of the smaller bores surrounding said leads and extending outwardly of said pipe, a glass seal about the periphery of the outer end of each sleeve, enclosing and supporting the outwardly extending leads, a pair of magnets, one positioned on each side of said pipe in alignment with said cavity, and means sealing both ends oi said pipe.

11. An electron discharge device, including a hollow metal pipe formed with a transverse passage through one wall leading to its central bore and forming therewith a central cavity, and a pair of smaller aligned transverse bores extending through opposite walls and communicating with said cavity, a cathode positioned within said cavity, cover means sealing the open end of said passage, a pair of cathode leads each attached at one end of said cathode and extending through said smaller bores outwardly of said pipe, means sealing the outer ends of said smaller bores and supporting said leads therein, a pair o magnets one positioned on each side of said pipe in alignment with said cavity and means sealing both ends of said pipe.

12. The combination according to claim 1l, in whi-ch said cathode comprises a hollow cylinder and a heating coil positioned therein, said cylinder being disposed coaxially with respect to said cavity with one end of said coil attached to one end of the cylinder, and in which one of said leads is connected to 'the other end of said cylinder and the other of said leads is connected to the other end of said heating coil.

PAUL GEORGES CHEVIGNY. CARSON lVlCKE-AG WHEELER.

REFERENCES CITED The following references are of record in the nle of this patent:

UNITED STATES PATENTS Number Name Date 1,951,141 Forney Mar. 13, 1934 2,075,876 Von Wedel Apr. 6, 1937 2,391,016 Gfinzton et al. Dec. 18, 1945 2,411,601 Spencer Nov. 26, 1946 2,417,789 Spencer Mar. 18, 1947 

